Quote:
|
washers? I didn't see any
|
That's the problem then.
You need insulating washers and eyelets like this otherwise the transistor will short to the fan speed controller case and fail. :
so the transistor case is electrically isolated from the case of the fan speed controller.
The eyelets are not labelled (they are the black items but the fit in the screw holes so the screws don't connect the case to the transistor. The isolating pad/washer can be mica or rubber and needs to be covered with heatsink paste so the heat but not electricity can move between the transistor and the finned case of the fan speed controller.
Mica washers or isolating pad:
